I would like to rotate a water outlet line 180 degrees using the water pressure as the force driving the rotation. Does anyone know of any designs for an application like this? Perhaps some type of a butterfly valve under tension to one side? As the pressure builds behind the closed butterfly, it opens the butterfly by rotating the outlet tube around the fixed butterfly valve. Then the rotation is reversed when the butterfly is fully open and the tension on the butterfly overpowers the water pressure? Thanks for any ideas.